How does a balloon payment work?

If I want to buy a house on a balloon payment then do I have to pay it off within a few years?

A balloon mortgage can be an excellent option for many home buyers. A balloon mortgage is usually rather short, with a term of five to seven years, but the payment is based on a term of 30 years. They often have a lower interest rate, and can be easier to qualify for than a traditional 30 year fixed mortgage. There is, however, a risk to consider. At the end of your loan term you will need to pay off your outstanding balance. This usually means you must refinance, sell your home or convert the balloon mortgage to a traditional mortgage at the current interest rates.